Shank and bit punch



July 9, 1929. E, PETERS Ei- AL I 1.720.435 SHANK AND BIT PUNCH FiledSept. 9, 192'? E QQ Ms w fi k :1

Patented July 9, 1929.

lll'l'llD STATES PATENT OFFlCE.

ARTHUR E. PETERS, UF PHILLIPSBUBG, NlJlW JERSEY, AND JESSE DITSON, OFLITTLE- IUN, COLORADO; ASSIGNGBE TO INGERSOLL-RAND COMPANY, OF JERSEYCITY, NEVJ JERSEY, A CORPORATION OF NEW JERSEY.

SHANE AND BIT PUNCH.

Application filed September This invention relates to devices for reiorming the bores of hollow articles, but more particularly to a fluidactuated device for pinning out the ends of the bores in drill steelsand other similar articles in which the entrance of the bores frequentlybecome restricted during the preceding sharpening operation.

One object of the invention is to drive a punch pin into the bore of adrill steel and withdraw it therefrom by rapidly repeated blows of thehammer piston against the anvil block whereby the punch pin is carried.

Another object is to provide aconvenient means for controlling theadmission of pressure fluid into the percussive element of the punch.

Other objects will. be in part obvious and in part pointed outhereinafter.

In the drawings showinga preferred modification of the invention,

Figure 1 is a longitudinal sectional elevation of a shank and bit punchconstructed in accordance with the practice or the invention and showingthe parts in position for driving the punch pin into the work,

F igure 2 is a view similar to Figure 1 il lustrating the position ofthe parts for withdrawing the punch pin from the work,

Figure 3 is a transverse view of the centering chuck taken throughFigure 1 on the line 3-3 looking in the direction indicated by thearrows, and

Figure 4 is a similar view of the throttle valve lever taken throughFigure 1 on the line iti looking in the direction indicated by thearrows.

Referring to the drawings, A designates the cylinder of a shank and bitpunch and B the piston chamber in which is disposed a reciprocatoryhammer piston C. The piston chamber B comprises an enlarged forwardportion D and a rearwardly reduced portion E. The piston C isproportioned accordingly and its rearward reduced portion F in thisinstance is constantly exposed to pressure fluid during the operationofthe machine.

Disposed at the front end of the cylinder A and projecting partlythereinto is a front head G which may be secured in operative positionin any suitable manner as for instance by the usual side bolts (notshown). The rearward end of the cylinder A is sealed 9, 1927. Serial N0.218,465.

by a back cylinder wasl'ier H which :torms a seat for and serves tocentralize a cylinder cap J with respect to the cylinder.

On one side of the cylinder A is formed a tapered valve chamber K toaccommodate a correspondingly tapered throttle valve L having a passage0 in constant communication with pressure fluid conveyed to the throttlevalve from any suitablesource of supply by a connection P. The throttlevalve L in this instance is provided with a stem Q; which is supportedat its outer end. by a bearing It preferably formed integrally with thecylindcr A and so spaced with respect to that portion of the cylinderwherein the valve chamber K is formed as to form a space S of suitableproportions to receive a throttle valve lever T whereby the throttlevalve L may be manipulated.

The throttle valve lever T comprises oppositely extending portions U andV curved slightly at their ends to prevent deflection of such instrumentor means as may be e1nployed for manipulating the throttle valve.Intermediate the ends of the throttle valve lever is formed a bore TV toreceive slidably the stem Q, and in one side of the lever adjacent thebore W is formed a slot X to permit contraction of the lever at thispoint for the purpose of clamping said lever to thestem Q. The meanswhereby this clamping eitiect is obtained in the present instanceconsist of a bolt Y which engages a notch Z in the stem Q, and hasthreaded on one end a nut 5 whereby the desired clamping etlect may beobtained.

In its assembled position, the throttle lever T will be inclined both inthe open and closed positions of the throttle valve L, the degree of.rotation of said throttle valve being limited by the cylinder in thebottom of the space S which forms an abutment for the throttle lever onopposite sides of the stem: Q.

In one side of the throttle valve L is a port 0 to afford communicationbetween the passage 0 and a port d in the cylinder A for the passage ofpressure fluid into the piston chamber B. The port d is in constantcommunication with a passage 6 having rear ward and forward ports 7 and9 both of which open into the reduced bore E of the cylinder.

As is customary in devices employing pie A portion D of thepistonchamber B for impellingithe piston forwardly.

Pressure fluid is conveyed to the end of the piston chamber B forimpcllr the piston C rearwardly through an inlet passage is which opensinto the piston chamber B near its front end and has its entrance end 0intermediate the ports and 9.

Intermediate the ends of the enlarged portion D of the piston chamber Bis formed an exhaust port p for exhausting the pressure fluid from bothends of the enlarged portion D, said exhaust port being controlled bythe head of the piston C.

Extending slidably through the front head, the cylinder and the pistonan anvil block g having a recess r in its front end to receive a punchpin 8 adapted to be driven into a hollow drill steel The punch pin 8 maybe secured in the anvil block 9 in any suitable manner, in the presentinstance a pin at extending transversely through the anvil block and thepunch pin is used for this purpose.

' The anvil block g illustrated is of a length to extend through thecylinder A and, in its retracted position through the cylinder cap J.The anvil block is guided in this instance near its front end by thefront head G and at a point near its rearward end by the back cylinderwasher H.

Near the front end of the anvil block 9 is a collar 0) which when theanvil block Q is in its rearwardmost position, extends into the pathofthe'piston C to' receive the blows thereof for driving the punch pin 8into the drill steel 2/. Somewhat similar means are provided forexposing the anvil block 9 to the blows of the piston C for driving saidanvil block in a rearwardly direction. These means in the presentinstance consist of a pair of semi-cylindrical collars w'which lie in agroove 3 in the anvil block q and are held against lateral movement by acoil spring- 2 which snugly engages the periphery of said collars w tohold them in the groove I Y 'Means are provided for restoring the anvilblock 9 to an intermediate position whenv ever the pressure used foractuating the anvil block is released therefrom. The means employedforthis purpose consist of a pair of rearward collars 2 which may abut ashoulder 3 in the cylinder cap J and are disposed slidably on therearward end of the anvil block 9. An opposed pair of col lars 4 aresimilarly disposed about the anvil block forwardly of the collars Q toseat either against a shoulder 5 of the anvil block or a ainst therearward surface (3 of the baelr cylinder washer H, depending upon theposition of the anvil block (1. The collars i3 and 4- are held inassembled position by a compression spring 7 which encircles them andalso acts thereagainst for actuating the anvil block 9 whenever thepressure exerted on said anvil block for compressing the spring 7 isreleased. At the rearward end of the anvil block g is formed a shoulderS which, when the anvil block is drawn forwardly, may engage the collars2 for compressing the spring 7 A convenient support for the drill steelt is provided in the form of a centering chuck -9 having a fork 10 solocated with respect to the punch pin 4; that when the drill steel t isdisposed within said fork 10, the hollow portion of the drill steel willlie in substantially the same plane as the longitudinal axis of thepunch pin a. The centering ehucl; in this instance is mounted on a rod1l whereto it is clamped by means of a bolt 12. The rod 11 extends intoan aperture 11-} in the cylinder A and is hold both against rotative andlongitudinal movement by a pin 14: extending transversely through thecylinder and the rod.

The operation of the device briefly described is as follows: Let it beassumed that at the beginning of the operation, th anvil block 9 is inthe intermediate position hereinbefore referred to, that is, theposition to which it will be automatically actuated by the spring 7. Ifthen, it be desired to drive the punch pin 8 into the drill steel t, theattendant may strike a blow on the end V of the throttle lever T tooscillate said throt tle lever to the position indicated in Figure l. Inthis position, the throttle valve will be open and pressure fluid maythen flow throughthe ports 0 and (I into the passage c, thence into therearward end of the reduced portion E of the piston chamber 13 as wellas into the rearward end of the enlarged portion D of the piston chamberfor actuating the piston forwardly against the collar o of the anvilblock, it being of course understood that the pressure of the drillsteel t against the punch pin 8 will be sufficient to compress thespring 7 as shown in Figure l and thus move the collar i; into the pathof the hammer piston C. At about the time the piston C is delivering itsblow against the collar 1) the rearward end of the passage 7c will beuncovered by the piston, thus permitting the flow of pressure fluidthrough the passage 0 into the front end of the piston chamber B todrive the piston C rearwardly. This reciprocation of the piston C maycontinue until the restricted portion of the bore in the drill steel Ihas been satisfactorily opened.

ill)

As is well known, the chilling effect of the punch pin 8 on the heatedend of the drill steel a will cause the said drill steel to contract onthe punch pin 8 to such an extent that it will cling thereto withsufficient force to enable the anvil block to be pulled to its extremeforward position whenever a pull 011 the drill steel is exerted. As aresult the anvil block 9 may be moved forwardly to such a position thatthe collar 4) will be witlr drawn out of the range of the blows of thehammer piston C and the collars to will then be advanced sulliciently toexpose them to the blows of the rearward end. of the piston C. 111 thisway the punch pin 8 will be readily withdrawn from the drill. steel thuspermitting the spring 7 to expand and force the anvil block 9 to itsintermediate position. In this position of the anvil block, the col.-lars 2 will bear against the collar B of the anvil block and the collars4 against the surface 6 of the back cylinder washer H and the anvilblock 9.

After the punching operation has been completed, the attendant may, bydropping the drill steel 6 on the end U of the lever T, tip the lever toits other extreme position, thus closing the throttle valve L and.shutting oil the supply of pressure fluid to the cylinder.

As will be readily seen, the present device forms a complete and compactunit of light weight and simple construction for punching hollowarticles. The method of controlling the admission of pressure fluid tothe punch is extremely simple as compared with other well known devicesof this type. In its extreme positions, the throttle lever T isinclined, thus indicating at all times the exact position of thethrottle valve L. This is a desirable feature in devices of thischaracter since it tends to eliminate accidents such as sometimes happenwhen the supply of air to the device is temporarily cut oil' and shortlyafterwards again turned on without closing the throttle valve.

We claim:

1. In a shank and bit punch the combination of a cylinder and piston, ananvil block extending through the piston, a punch pin carried by theanvil block and shoulders on the anvil block adapted to be selectivelyexposed to the blows of the piston for driving the punch pin into andout of the article intended to be punched, one of said shoulderscomprising a, pair of collar members encircling said anvil block and aspring holding said members in position on said block.

2. In a shank and bit punch the combination of a cylinder, a pistonhaving a hollow end, an anvil block extending through the piston, apunch pin carried by the anvil block, shoulders on the anvil blockadapted to be selectively exposed to the blows of the piston for drivingthe punch pin into and .out of an article intended to be punched, one ofsaid shoulders comprising a pair of collar members encircling said anvilblock, a spring holding said members in position on said block and aneck on said anvil block adapted to receive the collar members, saidpiston being adapted to slide over said collar members at its hollowedend.

In testimony whereof we have signed this specification.

ARTHUR E. PETERS. JESSE DITSON.

